The 12th Annual NON-COMMvention, the gathering of music-centric public radio stations and industry executives, has announced additions to the musical performance lineup.

Joseph Arthur, Beth Orton and Citizen Cope will join the previously announced Willie Nelson, Norah Jones, Sinead O’Connor, Paul Weller, Joe Jackson, Rufus Wainwright, Nada Surf, and a dozen additional artists to the May 17-19 event in Philadelphia. The music showcases will take place at World Cafe Live, adjacent to the WXPN/Philadelphia studios.